• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.8
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• pp.654-658
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• 2009

For investigation of surface leakage currrent of AlGaN/GaN heterostructures through etched GaN buffer surface and mesa wall, three kind of surface-leakage-test-patterns were fabricated. and we measured the surface leakage current of each patterns. In result of our work, the surface leakage current of pattern of which Schottky contact is formed on etched mesa wall is the largest. the leakage current through schottky contact on etched mesa wall is predominant in AlGaN/GaN heterostructures.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.299-302
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• 1995

Recently, we proposed a 3-D range-image measuring system for a slowly moving object by mechanically scanning a laser light beam emitted from a self mixing laser diode. In this paper, we introduced that every object moves along a straight line course, which is set diagonally against the semiconductor laser beam so that we can recognize each shape and size parameters of objects separately from the acquired 3-D range-image. We measured a square mesa on a square plane as an object. The measured velocity was 4.44mm/s and 4.63mm/s with an error of 0.56mm/s to 0.37mm/s. And thickness error of the mesa was 0.5mm to 0.6mm, which was obtained from the 3-D range-image of the standstill or moving object with thickness of 17.Omm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.89-90
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• 2009

Three kind of surface-leakage-test-patterns were fabricated and measured in order to investigate the surface leakage current of AlGaN/GaN heterostructures through etched GaN buffer surface and mesa wall. The pattern which contain the mesa wall has the largest surface leakage current among them. The leakage current due to the mesa wall is predominant source of the leakage current of AlGaN/GaN devices.

• TTA Journal
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• s.87
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• pp.191-200
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• 2003

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.1
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• pp.71-76
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• 1994

Schottky diodes have been fabricated using the SDB wafer, and their characteristics have been investigated. For comparison, conventional planar and etched most structure were made on the same substrate. The ideality factor and barrier height of the fabricated devices are found to be 1.03 and 0.77eV, respectively. Breakdown volttge of the etched mesa Schottky diode has been increased to 180V. whereas it is 90V for the planar diode. Schottky diode with an etched mesa exhibits twice improvement in breaktown voltage.

• 방재와보험
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• s.103
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• pp.72-74
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• 2004

• Clinical and Experimental Reproductive Medicine
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• v.21 no.3
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• pp.267-272
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• 1994

We studied the role of assisted fertilization(subzonal insemination, intracytoplasmic sperm injection) in enhancing fertilization and pregnancy rate in obstructive azoospermia. MESA was performed in the patients with congenital absence of the vas deferens and unreconstructable obstructive azoospermia. Sperm were aspirated microsurgically from various sites along the epididymal stump. Sperm were then washed on a mini-PercoH gradient or swim-up method and treated by 2-deoxyadenosine and pentoxifylline. Conventional IVF(group I, 14 cycles), SUZI(group II, 13 cycles) and ICSI(gruop III, 28 cycles) were carried out in 55 treatment cycles. The clinical results are as follows: 1. Fertilization rates for group I, II and III were 16.1 %,31.4% and 48.6%, retrospectively (p<0.05). 2. Clinical pregnancy rates for group I, II and III were 7.1 %,7.7%, and 32.1 'Yo, retrospectively. 3. In 5 of MESA-ICSI cycles, epididymal sperm from alloplastic spermatocele were used and 2 clinical pregnancies (40%) were obtained. According to our results the combined MESA-ICSI procedure is highly effcient in improving fertilization and pregnancy rate in congenital absence of the vas deferens and unreconstructable obstructive azoospermia.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.341-349
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• 2021

We studies to verify results similar to those of previous experiments, and their potential as a lighting device through optical characteristics experiments and resonance and optical characteristics simulations of array devices. The photonic quantum ring (PQR) device having a mesa diameter of 40 ㎛ and an internal hole diameter of 3 ㎛ was fabricated. Through the near-field observation of the fabricated device, it was found that the PQR device operates even at ㎂, and also that the mesa and hole devices are driven independently of each other. As a result of measuring the wavelength spectrum of the device according to the location, the coupling phenomenon due to mesa and holes was confirmed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.25-28
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• 2000

A capacitance-type humidity sensors in which porous silicon layer is used as humidity-sensing material was developed. This sensors was fabricated monolithically to be compatible with the typical IC process technology except for the formation of porous silicon layer. As the sensors is made as a mesa structure, the correct measurement of capacitance is expected because it can remove the effect of the parasitic capacitance from the bottom layer and another junctions. To do this, the sensor was fabricated using process steps such as localized formation of porous silicon, oxidation of porous silicon layer and etching of oxidized porous silicon layer. From completed sensors, capacitance response was measured on the relative humidity of 25 to 95% at room temperature. As the result the measured capacitance showed the increase over 300% at the low frequency of 120Hz, and showed little dependence on the temperature between 10 to $40^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.286-289
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• 2003

In the case of high voltage devices, junction termination plays an important role in determining the breakdown voltage of the device. The mesa junction termination has been demonstrated to yield nearly ideal breakdown voltage for 6H-SiC p-n junctions. However, such an approach may not be attractive because of the nonplanar surface, which is difficult to passivate. Moreover, In case of 4H-SiC, ideal breakdown voltage could not be achieved using mesa junction termination. For 4H-SiC planar junction termination technique is more useful one rather than mesa junction termination. In this paper, breakdown characteristics of the 4H-SiC device with planar junction termination, such as FLR(Field Limiting Ring), FP(Field Plate) and JTE(Junction Termination Extension), is presented. In the case of the FLR, breakdown voltage of 1800V is obtained. And breakdown voltage of 1000V and 1150V is also obtained for the case of FP and JTE case, respectively.